John h



(No Model.)

J. H. SHAW. DOOR CHECK.

No. 478,372. Patented July 5, 1892.

UNITED STATES PATENT DFFICE.

JOHN H. SHAW, OF NEW HAVEN, CONNECTICUT, ASSIGNOR TO THE SARGENT dzCOMPANY, OF SAME PLACE.

DOOR-CHECK.

SPECIFICATION forming part of Letters Patent No. 478,372, dated July 5,1892.

Application filed April 4, 1892. Serial No. 427,677. (No model.)

To aZZ whom it may concern:

Be it known that I, JOHN H. SHAW, of New Haven, in the county of NewHaven and State of Connecticut, have invented a new Improvement inDoor-Checks; and I do hereby declare the following, when taken inconnection with accompanying drawings and the letters of ref-- erencemarked thereon, to be a full, clear, and exact description of the same,and which said drawings constitute part of this specification, andrepresent, in

Figure 1, a plan view of the check complete; Fig. 2, a plan view of thepiston and its connections removed from the cylinder; Fig. 3, a sideview of the same; Fig. 4, a transverse section cutting on line was ofFig. 2; Fig. 5, a modification in the spring; Fig. 6, a plan view, andFig. 7 an edge view, of the bracket and saddle in a modified form; andFig. 8, another modification.

This invention relates to an improvement in that class of door-checkswhich consist of a piston and cylinder, the one attached to the linteland the other to the door, and so that in the opening of the door thetwo separate, and so that when the door'is closed the pis ton willre-enter the cylinder and, compressing the air therein, will serve as acheck to the closing door, so as to prevent its slamming.

In the usual application the cylinder is made fast to the door and thepiston to the lintel; but the result is the same whether this be thearrangement of the piston and cylinder or whether their positions bereversed. As the door swings in opening and closing,

the part attached to the door' necessarily moves in the arc of a circle.It, therefore, in a closed position the piston stands with its rod insubstantially the axial line of the cylinder, as it should do, theopening movement of the door will necessarily incline the pistonrod fromthat position, owing to the curve in which the parts move in separation,so. that there is unavoidably a swinging movement of the piston until itis entirely free from the cylinder, and as the door closes, to returnthe piston into the cylinder, there will be a like swinging movement ofthe piston after it enters the cylinder and, until it reaches its 1 homeposition. The piston therefore must necessarily have a certain extentoffreedom to swing in a plane at right angles to the axis on which thedoor swings, and in order to avoid undue friction between the piston andthe cylinder there must be little opposition to such swinging movementof the piston, and yet the piston must be held after it leaves thecylinder, so that its proper entrance to the cylinder on the closing ofthe door will be as sured.

Various devices have been made to yieldingly hold the piston topermitthe beforementioned swinging movement and yet insure the properentry of the piston into the cylinder. It is to this class of adjustingdevices for the piston that this invention particularly relates, theobject being a simple and yielding device whereby the object oftheinvention is accomplished; and the invention consists in theconstruction as hereinafter described, and particularly recited in theclaims.

A represents the cylinder, which is secured to the lintel or door, asthe case may be, in the usual manner and is of the usual construction.

13 represents the piston, and O the pistonrod, the piston being of anyof the usual constructions adapted to properly fit the interior of thecylinder.

D represents a bracket, by which the piston is secured to the door orlintel, as the case may be. In this bracket a saddle E is hung upon apivot F, the axis of the pivot being substantially parallel with theaxis on which the door swings. The piston-rod C is hung to this saddleupon a pivot G, the axis of which is parallel to the axis of the pivotF, the said pivot G being arranged between the piston and the pivot F.The piston swings freely on the pivot G from right to left.

The saddle E is constructed with shoulders II II to the right and leftof the pivot,'and the piston-rod is constructed with correspondingshoulders I I, the shoulders H being near the pivot F, on which thesaddle is hung, and the shoulders I upon the opposite side of the pivotG, and so that as the piston swings to the right or left, turningupon'its pivot G, the shoulder I on the side of the piston toward whichit is swinging'will approach the shoulder H, while the shoulder I uponthe opposite side of the piston will correspondingly recede from theshoulder ll of the bracket on that side, and vice versa.

The hinged portion of the saddle and piston-rodthat is to say, that partof the saddle and piston-rod between the shoulders on the saddle and theshoulders on the pistonrod-is made of cylindrical shape, as representedin Fig. 4;. Around this cylindrical portion a spiral spring J isarranged,one end of which bears upon the shoulders H H of the bracket,and the other end of the spring bears upon the shoulders I Iof thepiston-rod. lhe bracket and the shouldered part of the piston arenarrower than the diameter of the springs, as seen in Fig. 3, so thatthe hearing of the spring upon the piston and bracket is to the rightand left of the pivots only, thereby operating between the shoulderssubstantially the same as if there were two independent springs, onearranged between the two shoulders on one side of the pivot and theother spring arranged upon the opposite side of the pivot, as seen inFig. 5, and so that if the bracket be held firm as the piston swings inone direction, as to the left, and as indicated in broken lines in Fig.2, the spring will be compressed on the left-hand side; but so soon asthe piston is free the reaction of the spring will bring the piston backinto line again, the spring bearing between the shoulders of the bracketand the shoulders of the piston, so as to maintain the piston insubstantiallya direct line through the support of the bracket and thepivot on which the piston is hung.

It is necessary that the piston be adjustable, so that in setting thecheck in place the piston may be adjusted to operate properly withrelation to the cylinder. This adjustment may be accomplished in variousways, one of which is illustrated in Figs. 1 and 2, and is produced bymeans of adj usting'screws K and L through arms M N, projecting at theright and left from the saddle, and so that by withdrawing one screw andturning the other inward the inclination of the piston with relation tothe bracket may be readily varied. Other known adjusting devices may besubstituted for this arrangement-as, for illustration, that seen inFigs. 6 and 7, in which the saddle and bracket are clamped together bymeans of a binding-screw O, which forms the pivot upon which the saddlemay swing, and so that by loosening the screw the saddle may be turnedto the desired position, and when that position is attained the screwturned so as to clamp the two parts firmly together. This constructionof the connection between the piston and its saddle gives to the pistonthat freedom which is necessary in its movement into and from thecylinder, and the spring insures the normal position of the pistonnecessary for its proper entrance into the cylinder.

\Vhile preferring to make the shoulders on the piston between the pistonand the pivot on which it is hung and the shoulders on the saddle uponthe opposite side of said pivot, this relative position is notessentialas, for illustration, the shoulders on the piston may be theother side of the pivot, as seen in Fig. 8, and produce substantiallythe same result. It is therefore only essential to the invention thatthere shall be shoulders on the saddle at the. right and left of thepivots and corresponding shoulders on the piston, between whichshoulders of the piston and the shoulders of the saddle a spring orspringsare arranged, adapted to bear on the shoulders each side of thepivots and with substantially equal force.

I clai n1- 1. In a door-check consisting of a cylinder and a piston andin which the piston is withdrawn from the cylinder in the openingmovement of the door, the combination therewith of a saddle, thepiston-rod hung to said saddle upon a pivot the axis of which isparallel with the axis upon which the door is to swing, the saddleconstructed with shoulders to the right and left of the said pivot, andthe piston-rod constructed with corresponding shoulders, with a springbetween the shoulders of thepiston-rod and the shoulders of the saddle,and a bracket to which the said saddle is adjustably pivoted, the axisof the bracket-pivot being parallel with the axis of the pivot betweenthe saddle and piston-rod,substantially as described.

2. In a door-check consisting of a cylinder and a piston and in whichthe piston is Withdrawn from the cylinder in the openingmovement of thedoor, the combination therewith of a saddle, the piston-rod hung to saidsaddle upon a pivot the axis of which is parallel with the axis uponwhich the door is to swing, the saddle constructed with shoulders to theright and left of said pivot, and the piston-rod constructed withcorresponding shoulders, with a spiral spring around that portion of thepiston-rod and saddle between said shoulders, one end of which bearsupon the shoulders of the saddle and the other end upon the shoulders ofthe piston-rod, and a bracket to Which the said saddle is adj ustabl ypivoted, the axis of the pivot between the saddle and bracket beingparallel with the axis of the pivot between the saddle and piston-rod,substantially as described.

In testimony whereof I have signed this specification in the presence oftwo subscribing witnesses.

JOHN H. SHAW.

Witnesses:

NINA L. EGGLESTON, F. S. HAMLIN.

